Florisneide Rodrigues Barreto

Dengue: twenty-five years since reemergence in Brazil

This article revisits the epidemiology of dengue in Brazil, 25 years after its reemergence in the country, discussing the main determinants and implications for its control. The authors emphasize the clinical and epidemiological peculiarities of this viral disease in Brazil, which leads the world in both the number of cases reported and risk of occurrence of the disease. The article presents the changes occurring in the dengue epidemiological pattern in recent years, like the sudden age shift in the incidence of dengue hemorrhagic fever, and discusses possible associated factors. The article focuses specifically on the epidemic in Rio de Janeiro in 2008, this episodes impact on the international community, and the fear that the disease could spread to Europe. The authors conclude that the current situation emphasizes the need for the international scientific community to renew its efforts to generate knowledge allowing improvement and progress in the development of new tools and strategies for dengue prevention.

Modelling the dynamics of dengue real epidemics

In this work, we use a mathematical model for dengue transmission with the aim of analysing and comparing two dengue epidemics that occurred in Salvador, Brazil, in 1995–1996 and 2002. Using real data, we obtain the force of infection, Λ, and the basic reproductive number, R0, for both epidemics. We also obtain the time evolution of the effective reproduction number, R(t), which results in a very suitable measure to compare the patterns of both epidemics. Based on the analysis of the behaviour of R0 and R(t) in relation to the adult mosquito control parameter of the model, we show that the control applied only to the adult stage of the mosquito population is not sufficient to stop dengue transmission, emphasizing the importance of applying the control to the aquatic phase of the mosquito.

Spread pattern of the first dengue epidemic in the city of Salvador, Brazil

BackgroundThe explosive epidemics of dengue that have been occurring in various countries have stimulated investigation into new approaches to improve understanding of the problem and to develop new strategies for controlling the disease. The objective of this study was to evaluate the characteristics of diffusion of the first dengue epidemic that occurred in the city of Salvador in 1995.MethodsThe epidemiological charts and records of notified cases of dengue in Salvador in 1995 constituted the source of data. The cases of the disease were georeferenced according to census areas (spatial units) and epidemiological weeks (temporal unit). Kernel density estimation was used to identify the pattern of spatial diffusion using the R-Project computer software program.ResultsOf the 2,006 census areas in the city, 1,400 (70%) registered cases of dengue in 1995 and the spatial distribution of these records revealed that by the end of 1995 practically the entire city had been affected by the virus, with the largest concentration of cases occurring in the western region, composed of census areas with a high population density and predominantly horizontal residences compared to the eastern region of the city, where there is a predominance of vertical residential buildings.ConclusionThe pattern found in this study shows the characteristics of the classic process of spreading by contagion that is common to most infectious diseases. It was possible to identify the epicenter of the epidemic from which centrifugal waves of the disease emanated. Our results suggest that, if a more agile control instrument existed that would be capable of rapidly reducing the vector population within a few days or of raising the group immunity of the population by means of a vaccine, it would theoretically be possible to adopt control actions around the epicenter of the epidemic and consequently reduce the incidence of the disease in the city. This finding emphasizes the need for further research to improve the technology available for the prevention of this disease.

Epidemiologia do dengue em Salvador-Bahia,1995-1999

Since 1981, Brazil has registered dengue epidemic and simultaneous circulation of the DEN-1 and DEN-2 serotypes in over 2,700 municipalities. In Salvador- Bahia, located in the Northeastern region of the Country, two epidemic outbreaks occurred in the years of 1995 and 1996, with further endemic spread of the disease. This study analyses the incidence of the virosis within this municipal area, from 1995 to 1999, considering, among other variables, its distribution in the Sanitary Districts and density of Aedes aegypti. Registers of notified cases and the citys Vectorial Control Program were used as data source. The incidence rate of notified cases of dengue in 1995 and 1996, which were 691.4 and 393.5 per 100,000 inhabitants, respectively, decreased to 65 per 100,000 inhabitants in 1998. In the poorer Sanitary Districts, this index reached figures of over 800 per 100,000 inhabitants. The Premise Index for Aedes aegypti reached 54.1% in one of the Districts. Bearing in mind the relevance of the re-emergence of dengue in the world, the authors discuss the possible factors which condition the virus introduction, its epidemiological presentation over the course of four years, and the effectiveness of the vectorial combat (eradication) program.

Progressão da circulação do vírus do dengue no Estado da Bahia, 1994-2000

INTRODUCTION The strength of the re-emergence of dengue virus and the severity of these infections put this disease in the priority agenda of the institutions responsible for protecting the health of populations. Important for understanding the epidemiology of dengue nowadays refers to the knowledge of the patterns of spatial-temporal diffusion, though there is few research addressing this issue. This study describes the process of dissemination of dengue in the state of Bahia, from 1994 to 2000. METHODS This ecological study space-time, with the units of analysis, county, epidemiological week, month, trimester and year. There has been construction of the trend line and has been mapping the sequential occurrence of dengue in the municipality for the period. RESULTS There were 164,050 reported cases of dengue and the introduction of this virus in Bahia, unlike other states, occurred on a small city, though there is intermittency in spatial and temporal records of cases at the beginning of this epidemic. The virus circulated in all climatic zones fact what highlight its high transmission power. The highest intensity of detection of cases and territorial expansion was in the littoral (zone humid and half-humid) ideal area for the survive of the vector. CONCLUSIONS Hypothetically, the intermittent space-time pattern initially observed, could have allowed the control of the progression of the epidemic, if structured action to vectorial combat was carried out.

Risk factors for the incidence of dengue virus infection in preschool children

Objective  To estimate the seroincidence of dengue in children living in Salvador, Bahia, Brazil and to evaluate the factors associated.

Prevalence of nutritional deficiency in patients with pulmonary tuberculosis

OBJECTIVE: To determine the prevalence of nutritional deficiency among patients with pulmonary tuberculosis. METHODS: This was a cross-sectional study using data obtained from the Brazilian Case Registry Database and from the medical records of patients diagnosed with pulmonary tuberculosis (15-59 years of age) residing in one of the municipalities that make up the 16th Regional Health District of the state of Bahia. We calculated the incidence, lethality, and mortality rates, as well as the prevalence of nutritional deficiency, as evaluated by body mass index. Demographic, social, clinical, and epidemiological data were collected. RESULTS: Of the 72 confirmed cases of tuberculosis, 59 (81.9%) were in males, and 21 (29.2%) of the patients were in the 40-49 year age bracket. The majority (85.3%) described themselves as Mulatto or Black; 55.2% reported using alcohol; and approximately 90% were treated as outpatients. In the district and age bracket studied, the incidence of pulmonary tuberculosis was 30.6/100,000 population. Among the 72 patients, data regarding nutritional status was available for 34. Of those, 50% and 25%, respectively, presented nutritional deficiency at the beginning and at the end of treatment. No statistically significant differences were found between normal-weight and malnourished patients regarding the characteristics studied. CONCLUSIONS: The prevalence of nutritional deficiency was high among our sample of patients with pulmonary tuberculosis. This underscores the importance of nutritional follow-up for the assessment of tuberculosis treatment in the decision-making process regarding therapeutic interventions.

Chikungunya chronic disease: a systematic review and meta-analysis.

Background Chikungunya is a mosquito-borne disease caused by an arthritogenic alphavirus, with four genotypes: East Central South African (ECSA), West African, ECSA-diverged or Indian Ocean Lineage (IOL) and Asian lineage. Overall, the disease is self-limited; however, in some patients, joint pain and other non-specific symptoms can last for months or years. This systematic review and meta-analysis aims to estimate the proportion of people that self-report chikungunya-related chronic non-specific symptoms. Methods Medline, EMBASE, Global Health Library and Scopus were searched for articles published before March 2017. Case-control, cohort, cross-sectional, clinical trials studies and outcome-independent case series were eligible. It was estimated that the proportion of patients who did not recover, by virus genotype, and by the time between disease onset and assessment of chronic symptoms. Results A total of 38 studies were included in the review and 34 in the meta-analysis. Of 6532 chikungunya patients, 3157 did not recover fully after 3 months. The overall no recovery rate associated with chikungunya was 43% (95% CI, 35-52%); Inter-genotype group heterogeneity was observed, the highest prevalence in the ECSA-diverged genotype: 50% (95% CI; 40-60%), followed by the Asian lineage genotype: 36% (95% CI; 20-52%). After 12 months follow-up, the overall no-recovery rate was 21% (95% CI; 19-22%). Conclusion The evidence suggests that the prevalence of chronic discomfort associated with chikungunya illness varies by virus lineage. The proportion of people that do not fully recovered after chikungunya was high and, therefore, health authorities must prepare to treat patients with symptoms of long-lasting chikungunya adequately addressing the physical, psychological and social needs.

Relevance of transportation to correlations among criticality, physical means of propagation, and distribution of dengue fever cases in the state of Bahia

Dengue infection is a public health problem with a complex distribution. The physical means of propagation and the dynamics of diffusion of the disease between municipalities need to be analysed to direct efficient public policies to prevent dengue infection. The present study presents correlations of occurrences of reported cases of dengue infection among municipalities, self-organized criticality (SOC), and transportation between areas, identifying the municipalities that play an important role in the diffusion of dengue across the state of Bahia, Brazil. The significant correlation found between the correlation network and the SOC demonstrates that the pattern of intramunicipal diffusion of dengue is coupled to the pattern of synchronisation between the municipalities. Transportation emerges as influential in the dynamics of diffusion of epidemics by acting on the aforementioned variables.

The spatiotemporal trajectory of a dengue epidemic in a medium-sized city

Understanding the transmission dynamics of infectious diseases is important to allow for improvements of control measures. To investigate the spatiotemporal pattern of an epidemic dengue occurred at a medium-sized city in the Northeast Region of Brazil in 2009, we conducted an ecological study of the notified dengue cases georeferenced according to epidemiological week (EW) and home address. Kernel density estimation and space-time interaction were analysed using the Knox method. The evolution of the epidemic was analysed using an animated projection technique. The dengue incidence was 6.918.7/100,000 inhabitants; the peak of the epidemic occurred from 8 February-1 March, EWs 6-9 (828.7/100,000 inhabitants). There were cases throughout the city and was identified space-time interaction. Three epicenters were responsible for spreading the disease in an expansion and relocation diffusion pattern. If the health services could detect in real time the epicenters and apply nimbly control measures, may possibly reduce the magnitude of dengue epidemics.